The invention is concerned with a magnetically stabilized, sealed, cross flow CO.sub.2 laser to be used in an airborne environment. In the system, the operating voltage is dependent on the lengths of the discharges in the laser. To turn the entire discharge region on would require plasma breakdown voltages in excess of 10 kv and operating voltages on the order of 6-7 kv. Both of these voltages are troublesome in airborne applications and require greater internal insulation for the laser. By splitting the discharge, the breakdown voltages can be kept below 5 kv with corresponding operating voltages of 3-3.5 kilovolts. The difficulty encountered in extending this technique to multiple discharges in that each plasma has an associated cathode dark space. These are low or zero gain regions for lasing. Hence, the more discharges there are, the greater length of active media is occupied by dark spaces.
Another problem associated with the starting of the two discharges is that whichever discharge fires first will then provide a low impedance path to ground for the other unsaturated discharge. This is further complicated since the entire outside of a laser must be maintained at ground potential (except the high-voltage input leads) in the system.